X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fopt%2Freassoc.c;h=e5ac876263f326c1bb58fe7a72e8930c440632e4;hb=8d4189c67b88556b13e81e6dee9178f8b1168d28;hp=b7cfe70133f5ff43bb3b55ce015ca5f4afc0d007;hpb=7583c9feb0b5e90bed8e3f9a666718a7d9d3f56f;p=libfirm diff --git a/ir/opt/reassoc.c b/ir/opt/reassoc.c index b7cfe7013..e5ac87626 100644 --- a/ir/opt/reassoc.c +++ b/ir/opt/reassoc.c @@ -8,27 +8,26 @@ * Copyright: (c) 1998-2004 Universität Karlsruhe * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. */ - #ifdef HAVE_CONFIG_H -# include "config.h" +#include "config.h" #endif -# include "irnode_t.h" -# include "irgraph_t.h" -# include "irmode_t.h" -# include "iropt_t.h" -# include "ircons_t.h" -# include "irgmod.h" -# include "dbginfo.h" -# include "iropt_dbg.h" -# include "irflag_t.h" -# include "irgwalk.h" -# include "reassoc_t.h" -# include "irhooks.h" -# include "irloop.h" -# include "debug.h" - -static firm_dbg_module_t *dbg; +#include "irnode_t.h" +#include "irgraph_t.h" +#include "irmode_t.h" +#include "iropt_t.h" +#include "ircons_t.h" +#include "irgmod.h" +#include "dbginfo.h" +#include "iropt_dbg.h" +#include "irflag_t.h" +#include "irgwalk.h" +#include "reassoc_t.h" +#include "irhooks.h" +#include "irloop.h" +#include "debug.h" + +DEBUG_ONLY(static firm_dbg_module_t *dbg;) typedef struct _walker_t { int changes; /* set, if a reassociation take place */ @@ -37,13 +36,13 @@ typedef struct _walker_t { typedef enum { NO_CONSTANT = 0, /**< node is not constant */ REAL_CONSTANT = 1, /**< node is a Const that is suitable for constant folding */ - CONST_EXPR = 4 /**< node is a constant expression in the current context, + REGION_CONST = 4 /**< node is a constant expression in the current context, use 4 here to simplify implementation of get_comm_Binop_ops() */ } const_class_t; /** * returns whether a node is constant ie is a constant or - * is loop invariant + * is loop invariant (called region constant) * * @param n the node to be checked for constant * @param block a block that might be in a loop @@ -54,25 +53,28 @@ static const_class_t get_const_class(ir_node *n, ir_node *block) if (op == op_Const) return REAL_CONSTANT; + + /* although SymConst's are of course real constant, we cannot + fold them, so handle them like region constants */ if (op == op_SymConst) - return CONST_EXPR; + return REGION_CONST; /* * Beware: Bad nodes are always loop-invariant, but - * cannot handled in later code, so filter them here + * cannot handled in later code, so filter them here. */ if (! is_Bad(n) && is_loop_invariant(n, block)) - return CONST_EXPR; + return REGION_CONST; return NO_CONSTANT; } /** * returns the operands of a commutative bin-op, if one operand is - * a constant in the current context, it is returned as the second one. + * a region constant, it is returned as the second one. * * Beware: Real constants must be returned with higher priority than - * constant expression, because they might be folded. + * region constants, because they might be folded. */ static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c) { @@ -85,10 +87,22 @@ static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c) assert(is_op_commutative(get_irn_op(binop))); switch (class_a + 2*class_b) { - case REAL_CONSTANT + 2*NO_CONSTANT: case REAL_CONSTANT + 2*REAL_CONSTANT: - case REAL_CONSTANT + 2*CONST_EXPR: - case CONST_EXPR + 2*NO_CONSTANT: + /* if both are constants, one might be a + * pointer constant like NULL, return the other + */ + if (mode_is_reference(get_irn_mode(op_a))) { + *a = op_a; + *c = op_b; + } + else { + *a = op_b; + *c = op_a; + } + break; + case REAL_CONSTANT + 2*NO_CONSTANT: + case REAL_CONSTANT + 2*REGION_CONST: + case REGION_CONST + 2*NO_CONSTANT: *a = op_b; *c = op_a; break; @@ -105,14 +119,15 @@ static void get_comm_Binop_ops(ir_node *binop, ir_node **a, ir_node **c) static int reassoc_Sub(ir_node **in) { ir_node *n = *in; - ir_node *block = get_nodes_block(n); ir_node *right = get_Sub_right(n); + ir_mode *rmode = get_irn_mode(right); + ir_node *block; - /* FIXME: Do not apply this rule for unsigned Sub's because our code - * generation is currently buggy :-) - */ - if (! mode_is_signed(get_irn_mode(n))) - return 0; + /* cannot handle SubIs(P, P) */ + if (mode_is_reference(rmode)) + return 0; + + block = get_nodes_block(n); /* handles rule R6: * convert x - c => (-c) + x @@ -122,9 +137,8 @@ static int reassoc_Sub(ir_node **in) * */ if (get_const_class(right, block) == REAL_CONSTANT) { ir_node *left = get_Sub_left(n); - ir_node *block = get_nodes_block(n); - ir_mode *mode = get_irn_mode(n); - dbg_info *dbi = get_irn_dbg_info(n); + ir_mode *mode; + dbg_info *dbi; ir_node *irn, *c; switch (get_const_class(left, block)) { @@ -132,7 +146,7 @@ static int reassoc_Sub(ir_node **in) irn = optimize_in_place(n); if (irn != n) { exchange(n, irn); - *in = irn; + *in = irn; return 1; } return 0; @@ -142,9 +156,12 @@ static int reassoc_Sub(ir_node **in) /* already constant, nothing to do */ return 0; } + mode = get_irn_mode(n); + dbi = get_irn_dbg_info(n); - c = new_r_Const(current_ir_graph, block, mode, get_mode_null(mode)); - irn = new_rd_Sub(dbi, current_ir_graph, block, c, right, mode); + /* Beware of SubP(P, Is) */ + c = new_r_Const(current_ir_graph, block, rmode, get_mode_null(rmode)); + irn = new_rd_Sub(dbi, current_ir_graph, block, c, right, rmode); irn = new_rd_Add(dbi, current_ir_graph, block, left, irn, get_irn_mode(n)); @@ -152,7 +169,7 @@ static int reassoc_Sub(ir_node **in) get_Sub_left(n), c, get_Sub_left(n), c)); exchange(n, irn); - *in = irn; + *in = irn; return 1; } @@ -183,7 +200,7 @@ static ir_mode *get_mode_from_ops(ir_node *op1, ir_node *op2) * reassociate a commutative Binop * * BEWARE: this rule leads to a potential loop, if - * two operands are are constant expressions and the third is a + * two operands are region constants and the third is a * constant, so avoid this situation. */ static int reassoc_commutative(ir_node **node) @@ -210,7 +227,7 @@ static int reassoc_commutative(ir_node **node) c_t2 = get_const_class(t2, block); if ( ((c_c1 > NO_CONSTANT) & (c_t2 > NO_CONSTANT)) && - ((((c_c1 ^ c_c2 ^ c_t2) & CONST_EXPR) == 0) || ((c_c1 & c_c2 & c_t2) == CONST_EXPR)) ) { + ((((c_c1 ^ c_c2 ^ c_t2) & REGION_CONST) == 0) || ((c_c1 & c_c2 & c_t2) == REGION_CONST)) ) { /* All three are constant and either all are constant expressions or two of them are: * then applying this rule would lead into a cycle * @@ -258,7 +275,7 @@ static int reassoc_commutative(ir_node **node) DBG((dbg, LEVEL_5, "Applied: %n .%s. (%n .%s. %n) => (%n .%s. %n) .%s. %n\n", c1, get_irn_opname(n), c2, get_irn_opname(n), - t2, c1, get_irn_opname(n), c2, get_irn_opname(n), t2)); + t2, c1, get_irn_opname(n), c2, get_irn_opname(n), t2)); /* * In some rare cases it can really happen that we get the same node back. * This might be happen in dead loops, were the Phi nodes are already gone away. @@ -266,7 +283,7 @@ static int reassoc_commutative(ir_node **node) */ if (n != irn) { exchange(n, irn); - *node = irn; + *node = irn; return 1; } } @@ -303,18 +320,32 @@ static int reassoc_Mul(ir_node **node) t1 = get_binop_left(add_sub); t2 = get_binop_right(add_sub); - in[0] = new_rd_Mul(NULL, current_ir_graph, block, c, t1, mode); - in[1] = new_rd_Mul(NULL, current_ir_graph, block, c, t2, mode); + /* we can only multiplication rules on integer arithmetic */ + if (mode_is_int(get_irn_mode(t1)) && mode_is_int(get_irn_mode(t2))) { + in[0] = new_rd_Mul(NULL, current_ir_graph, block, c, t1, mode); + in[1] = new_rd_Mul(NULL, current_ir_graph, block, c, t2, mode); - mode = get_mode_from_ops(in[0], in[1]); - irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); + mode = get_mode_from_ops(in[0], in[1]); + irn = optimize_node(new_ir_node(NULL, current_ir_graph, block, op, mode, 2, in)); - DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n", - t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c)); - exchange(n, irn); - *node = irn; + /* In some cases it might happen that the new irn is equal the old one, for + * instance in: + * (x - 1) * y == x * y - y + * will be transformed back by simpler optimization + * We could switch simple optimizations off, but this only happens iff y + * is a loop-invariant expression and that it is not clear if the new form + * is better. + * So, we let the old one. + */ + if (irn != n) { + DBG((dbg, LEVEL_5, "Applied: (%n .%s. %n) %n %n => (%n %n %n) .%s. (%n %n %n)\n", + t1, get_op_name(op), t2, n, c, t1, n, c, get_op_name(op), t2, n, c)); + exchange(n, irn); + *node = irn; - return 1; + return 1; + } + } } return 0; } @@ -336,11 +367,14 @@ static void do_reassociation(ir_node *n, void *env) res = 0; - /* reassociation works only for integer or reference modes */ - if (op->reassociate && (mode_is_int(mode) || mode_is_reference(mode))) { - res = op->reassociate(&n); + /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */ + if (mode_is_float(mode) && get_irg_fp_model(current_ir_graph) & fp_strict_algebraic) + break; + + if (op->ops.reassociate) { + res = op->ops.reassociate(&n); - wenv->changes |= res; + wenv->changes |= res; } } while (res == 1); @@ -381,23 +415,33 @@ void optimize_reassociation(ir_graph *irg) /* Handle graph state */ if (env.changes) { - if (get_irg_outs_state(irg) == outs_consistent) - set_irg_outs_inconsistent(irg); + set_irg_outs_inconsistent(irg); set_irg_loopinfo_inconsistent(irg); } } +/* Sets the default reassociation operation for an ir_op_ops. */ +ir_op_ops *firm_set_default_reassoc(opcode code, ir_op_ops *ops) +{ +#define CASE(a) case iro_##a: ops->reassociate = reassoc_##a; break + + switch (code) { + CASE(Mul); + CASE(Add); + CASE(Sub); + CASE(And); + CASE(Or); + CASE(Eor); + default: + /* leave NULL */; + } + + return ops; +#undef CASE +} + /* initialize the reassociation by adding operations to some opcodes */ void firm_init_reassociation(void) { -#define INIT(a) op_##a->reassociate = reassoc_##a; - INIT(Mul); - INIT(Add); - INIT(Sub); - INIT(And); - INIT(Or); - INIT(Eor); -#undef INIT - - dbg = firm_dbg_register("firm.opt.reassoc"); + FIRM_DBG_REGISTER(dbg, "firm.opt.reassoc"); }